Centerless grinding machine attachment



April 20, 1943;

A." F. MADISON CENTERLESS GRINDING MACHINE ATTACHMENT Filed May 9, 1946 3 Sheets-Sheet l April 20, 1948. A. F. MADISON 2,440,148

CENTERLESS GRINDING MACHINE ATTACHMENT Filed May 9, 1946 5 Sheets-Sheet 2 April' 20, 1948.

A. F. MADISON GBNTERLESS GRINDING MACHINE ATTACHMENT Filed May 9, 1946 I 3 Sheets-Sheet 3 Patented Apr. 20, 1948 QFFICE oEi I'r ERLI'iSS MACfiifiE ATTACHMENT Bower Roller-"Bearing (imiipaiiyg betioit; Michr,

a corporation of Michigan" Application Mai 9,

20 claims;

This invention relates togrind ng macliliies',

and in particular, to so called centerlessjgrindifig machines for grinding the internal surfaces'of annular workpieces such as Bushinga sleeves, hearing cones, retaining rings andtl'ie' like. w

One object of this invention is to provide ,an' attachment for centerles's grinding machines wherein a plurality of annular workpiecefs 'may be internally ground simultaneously with 11'1"- ternally tapered surfaces.

Another object is to provide an attachmentfor centerless grinding machines wherein'a plurality of annular workpieces with internally tapered surfaces are supported'androtate'd in axially off"- set relationship for simultaneous grindinglbya grinding wheel engaging such surfaces.

Another object is to provide'an attachment tor centerless grinding machines as set forthm'the preceding objects wherein the workpieces are supported in axially offset relationship between a flanged regulating roll, a" flanged supportroll and a flanged pressure roll against a rotatable" backing member, adjusting means beingprovi'ded for positioning the rolls in proper relationship;

Another object is to provide anattachrnentlior a c'enterless grinding ma'chineras set forth in the object immediately preceding; wherein the" sup:- port roll and pressure rolls are" each made; up" of two subsidiary rolls to take care' of the difierenc in speed of'rotatiori' of the two workpieces being simultaneously ground, means being preferably provided for adjusting one subsidiary roll later ally" relatively to the other roll in ord'ento cor rectly position the two internally tapered work'- pieces in the correct offset relationship.

Another object is to providea modified attachment for simultaneously grihding internally" tapered workpieces mounted and driven in 1am; ally offset relationship wherein one workpiecejis' supported against a backing member and the other workpiece is supported against'anauxiliary backing member positioned between the two workpieces.

Another object is'to provide afurthermodified attachment for centerless grinding machlnes'for simultaneously grinding internally tapered work"- pieces mounted and driven in laterally offsetrelationship wherein one workpiece is supported" against a backing member" and theother'worb.

piece is supported in laterally offset relationship against' the first workpiece whereby one workpiece serves as a backing. member fortheiothef workpiece.

Other objects and advantagesoftheinvention will "become apparent during the courseof' the 194e,;sefiaiiia; 668551 e'cempehyin draw- I V n view off-an attachment fora eiiteri es'sg'rindin nfachine' 'according to a. L preferred embddirrlent-Of theirivent'ion partly in section'if diately'abovethe support 5 essii e-rolls'omitted and with on?! portions of the machine t. te ny: t :n z'i z fi e epnih o hw nte'iiless' rindifigimachirreattachrfient,taken awntheir 1; M p

' rticafl sectionalong theline3 3 1 in 1', snowing;tlrefworkpieces and their 1'6 supi' brfiii'g" mechanism;

figure 4 is a vertic'a y inclined section along the line 4 1131' 2.sliowing-the-adjustments for the regiilatin'grolli'support'rolls and pressure rolls; 7 s g V p 5 is avertical section along the zigzag liliesa ne ed in v V. y

ngmeeista:r meu eryi plan view, partly in liorizoniiail"seiltiliui M di modification employing an auxiliary hacking member'ior the .outer RPEWQQ 1 A h l 'Figurei'l"is'jan endelevationpf the modification shown" in Figure 6; with the" grinding wheel omitted; rigznewsusai art; The centeriess grinding machine shown, as de fromftheattachnient and-modifications of the pr'eserit invention, is of'thetypeshown generally in the U. S, patent to Blood et at, No; 21050548zieefanteeinugu e 1 1;, 1936; fora Grindin'g" machine; lts'jdetails no partof the for bunting and'dnvi ngthe" attachments, which areis'ubstitutedfor"the conventional devices for holding a'ndoiivin'g t workpiece" as employed in ontentment efifierlss grinding machines of suchic nventlonal rindin achmes grind but'o'neworkpiece at a tiniewhereas the 55 present attachment and itsinodifications enable ther than" providing means 3 them to grind two workpieces at one time, thereby greatly increasing the volume of production obtainable from a given machine over a given period of time while maintaining the same high precision hitherto obtained in grinding single workpieces at one time.

For the purposes of the present invention, Fi ures 1 and 2 show diagrammatically the supporte ing and driving mechanism of a conventional centerless grinding machine of the above de-- scribed type as consisting of a bed having longitudinal guideways Illa, such asdovetail guides, along which a carriage II is reciprocable.

(Figure 2) carrying on its upper end the base 43 Pivotally mounted on the carriage H is a work head |2 in the form of a turntable swiveled thereon around a pivot indicated by the dotted line I211. The carriage H is reciprocable by the. conventional power-operated means (not shown) The hollow shaft 28 (Figures 1 and 2) is provided with a longitudinal bore 35 in which is journaled an ejector shaft 36 operated by any conventional and well-known mechanism. Secured to one end of the ejector shaft 36, as by the pin 31, is the hub 38 of an ejector 39 having a radial arm. 40 with an arcuate ejecting member 4| mounted on the outer end thereof and arranged to swing partially around the periphery of the regulating wheel or roll 30 in an upward direction to expel workpieces in a manner sub- 1 sequently to be described.

so as to advance and withdraw the workpieces:

from the grinding wheel.

Likewise mounted upon the bed In and rising from one end thereof and extending thereacross is a bridge member or grinding head support |3 having transverse guideways |3a in which a grinding head cross slide I4 is reciprocably mounted. The grinding head cross slide is also reciprocated by conventional means such as the screw shaft |4a threadedly engaging a threaded nut |4b on the underside of the cross slide l4 and journaled in a boss |4c extending upwardly from the grinding head support l3. The screw' shaft Mat is intermittently rotated by. conventional timing means (not shown), the conventional means frequently employed being a cam-controlled mechanism so that the cross slide I4 is fed transversely only while grinding contact is actually maintained with the" workpiece.

Journaled on the grinding, head cross slide 14' transversely thereof is a grinding wheel shaft |'5' which passes through a bore I5a in a housing [5b and is rotated at a high speed by any wellknown or conventional means. .Mounted on the inner end of the grinding wheel shaft I5 is a grinding wheel l6 of a conventional type.

Reciprocably mounted in a guideway H such as a T-slot, in the work head (Figure 1) is a vertical regulating roll support l8 having a pilot rib l9 extending into the guideway. l1 and clamped therein by means of aclamping' bolt passin through a bore a (Figure2) in the regulating roll support l8 and threadedly'engaging a clamping member 2| disposed within the guideway l1.

The regulating roll support I8 is provided with a transverse threaded bore 22 into which is threaded a screw-shaft 23 journaled in the bore 24 of a vertical boss 25 and having a hand wheel 26 mounted on the outer end thereof. When the clamping bolt 20 is loosened, therefore, the turning of the screw shaft 23 by means of the hand wheel 26 moves the regulating roll support l8 to and fro along the guideway o-r T-slot I! to the desired position of adjustment, whereupon it is clamped in that position by tightening the clampingbolt 20.

Journaled in the longitudinal'bore 21in the upper end of the grinding wheel support I8 is a tubular shaft 28 carrying a pulley 29 at one end thereof and a'regulatingwheel or roll, generally designated 30, at the other end. The regulating wheel 30 is keyed at 3| to the hollow shaft 28 and at its periphery is provided with steppedj surfaces 32 and 33 of large andsmaller diameters separated from one another by an annular abutment shoulder 34. v

Rising from the work-head I2 is a post 42 ;of a vertical support 44, the base 43 being secured-to the post 42 by the cap screws or bolts 45 threaded therethrough. The vertical support 44 isprovided with a horizontal bore 46 in which is mounted a sleeve 41 secured therein by a set screw 48 threaded through the transverse threaded bore 49 (Figure 1). Journaled in the inner. bore 50 of the sleeve 41 is a backing shaft 5| having a retaining collar 52 pinned as at '53 to the rearward end thereof and having a cupshaped backing member 54 integral with the opposite or forward end thereof.

The backing member 54 is provided with an annular contact face 55 for engagement with the rear face 56 of an annular workpiece 51 having a tapered internal bore 58 to be ground, a front face '59 and a cylindrical peripheral surface 50 adapted to engage and roll upon the peripheral surface'32 of the regulating wheel or roll 30. A similar workpiece 6| similarly provided with an internal tapered'bore 62, rear and front faces 63 and 6-4 and a peripheral surface 65 engages and rolls upon the peripheral surface 33 of the regulating wheel 35 with its rear face 63 in engagement with the annular shoulder 34. The workpieces 51 and 6|, for purposes of illustration only,

' are shown as representing bearing cones or external bearing races for tapered roller bearings for which the present invention provides a greatly enhanced rate of production, when using a given number of centerless grinding machines.

The table II is provided with an upstanding portion 66 to which is bolted, as at 61, the base 58 of a vertical support roll bracket 69 having an elongatedportion in slightly inclined relatively to the horizontal plane. The elongated portion 69 is providedwith an undercut grooved guideway consisting of a T-slot H in which a slide 12 with a pilot rib 12a. is reciprocably mounted. Extending downwardly through a bore 73 in the slide 12 is a clampin bolt 14 threaded into a clamping. member 75 (Figure 2) lodged in the guideway H. The slide 12 is likewise provided with a longitudinal threaded bore 16 into which is threaded a screw shaft 11 having a reduced diameter portion 18 journaled in a bore 19 in an upstanding portion Bil of the elongated portion 10. Secured to the outeren-d of the reduced diameter portion 18 is a knurled hand wheel 8| for rotating the screw shaft 10 and thereby reciprocating the slide 12 along the grooved guideway 1|. The clamping bolt 14 is loosened during such adjustment and tightened after the adjustment has been made. a

The forward end of the slide 12 is provided with forwardly extending spaced arms 82 (Figure 1) having aligned grooves 83 and 84 (Figure 4) of partially circular cross-section resembling bores, the sides of which have been cut away. Mounted in the grooves 83 and 84 is a shaft 85 having flattened end portions 86 and .81 withlongitudinal slots 88 adapted torecei-ve clamping bolts 89 threaded into correspondingly threaded holes in the arms 82.

The shaft -85 is provided with an annular shoulder :90 adjacent one end thereof, and this shoulder serves as an abutment for the hub 9| of an eccentric bushing '92 mounted on the shaft 85 and adjustable by being turned relatively thereto. A set-screw 93 threaded into a trans- --verse bore94in the hub 9| serves to lock the cocentric bushing 92 its-adjusted position relativelyto the shaft 85.

Mounted for rotation upon the eccentric bushing 92 (Figure 4) isa workpiece support-r011 95 having a peripheral surface 96 which engagesthe peripheral surfacegfiii of the outer workpiece til, the face 3 hereo engagin h a tment shoulder 91 of a peripheral abutment flange 98 on the support roll -95. Mounted directly upon the shaft 85 and rotatable relatively thereto is a smaller support roll Bil-having a peripheral sur ;face I90 engaging the peripheral surface 60 of the inner workpiece 51. The support roll 99 abuts the end of the eccentric sleeve 92 (Figure 4) and also the adjacent side wall of the support roll 95, I

and is provi'ded with a peripheral groove I III adjacent the latter, so as to space the peripherm surface Hi axially a slight distance therefrom. A collar I02 mounted on the shaft 85 serves to retain the support rolls 95 and99 in axial adjustment, and forthis purpose the collar I92 is provided with a set screw I03 threaded into a transverse threaded bore I04. The outer'wall of the support roll 95'abuts-a shoulder Hi5 adjacentthe "hub 9 I of theeccentric bushing 92.

Rising from the slide I2is a post I95 terminating in a horizontal boss IB'I having a :bore I98 therethrollgh. Journaled-in the bore I08 is a --shaft Hi9'havinganarm tin-secured to'the rearwardend-thereof and having a bracket H I'keyed as-at N 2 to the forward end thereof (Figure 2).

The upper end of the bracket II Iis provided with an --elongated portion H3 having an undercut grooved guideway consisting ofa T-slot H4. Re-

'ciprocably mountedupon the elongated portion H3 ofthe bracket III is an arm I;I5ihaving a pilot rib IIS extending downwardly toward the 'T-slot H4 and having a clamping bolt -II-1 threaded into a clamping member II-8 lodged within 'the'T-slot H4. The arm "H5 is provided with abifurcated outer end II 9 upon which are mountedapair of-abutting pressure rolls I20and -I'2 Iwhich serve as pressure applicators, the manner of mounting being the same as thatpreviously described in connection with-the support rolls I951and-99 and shown in- Figure 4,-the corresponding parts being similarly designated. Thus, the

pressure roll I20 (Figure 5) is provided with an eccentric adjustment relatively to the upper shaft 8529Jld the pressure roll' I H rotatable thereon just as the support roll 95 isprovided with an eccentricadjustment relatively to the lower shaft ,il5rzand to; the support roll 99 mounted thereon.

:The pressure roll I20 is-provided witha peripheral -.ahutment flange I22 having an abutment shoulder I23 similar, in construction a andv purpose. to the abutment-l flange-won the s pp t 1l' In order to. urge the workpieces-i 51: .and G I into engagement with the'backing member .54 :and abutment .flangesiiia and I 22 respectively, the lvarious axescof rotation are tilted I relatively to one another as .shownaini-Fig. 5.. :In particular,

'tihezrearward-end of the regulating-wheel shaft 28: istiltedsupwardly so; as to incline the-axis: of

rotation: luv-thereof upwardly relatively to. the

' allel to the axes of rotation .of the rolls 99 and HI respectively. 'As a -consequence, when the regulating wheel or-roll 39 is rotated, it constantly u es the workplaces and SI rearwardly against their respective abutments and maintains them in a fixed position axially during thegrinding operation.

The arm LII! l lig ure 2) is'yieldingly urged in an upwarddirection so as to .urge the pressure rolls 120 and I2 I "downwardly against the workpieces :5.1 and EI' by the usual conventionaimeans well known in centerlesstgrindingmachines of the type to which the present invention is :applied,1for example by springs (not shown). In such machinesaiso, conventional-means, such as a cam (not shown) is provided for-swinging the arm III! downwardly-land thereby lifting the pressure rolls I20 and HI out ofcontact with the workpieces :51 and .BI when the'grinding operation hasbeen completed, additional means, such as aicam (not shown) being likewise provided to operate in timed relationship therewith. and rotate .theejector shaft (Eizure 2.) clockwise to swing the r ejectoraarm M landlejectortd I i upwardly to eject the :ground workpieces 51 and GI while the pressure rolls I29 and MI aretswung out of the way. Finally, in such machines, inclined guide troughs orthe like are tprovidedtabove the arm I15 and pressure mile 120 and I to contain and feed thezungroundlworkpiecesiil and BI downwardly to the POSitiOIlSAShOWI-iill Figure 2 and similar inclined guid troughs are provided above the regulating wheel :or roll :39 to carry away the workpieces 5:1 and M rafter they-have been ground and ejected :by the .ejector :M as. it swings upwardly.

O rat n of th f rm stor in Fi ur 1 t 5 incl ve res tt n up themach n wi hthe orm. of at achment shown in :E eu esi t 5 incl si a imm e o a ustments ar made e or p ducti n indin s commencedabut 'face as of th ba kin -aincmbe d i ac um ly trued so as to rotate evenly. The abutment s ul s '91 and I 3; ii-the suppo rol and pr ss r 11 i720 e nect elvate hcn1 md up by 0Qsening:' he:h 1t t ndslidin th j t .-:8=5, axially until the saidshoiiliiers lielin the same plane as the ahutmentashouldor :3 4:, of. the mo ulating wheel orlroll 30 ,at theirrespectivepoints of contact with the workpiecev 51 and IiI,= these flanges being also adjustedliio be i par lel I to the abutment face 55 .of the checkin .amcmb 54. "The support musk-; and aaarcrthonuadiu o y moving the slide 12: (Figure-2,) by means of the screw shaft T1 andhand wheelidlzimtil the. inner workpiece 51 is exactly .centeredgwithg respect to the axis ofirotation I25 of theibacking member 54. In a, similaramanner, the regulating wheel ,39, is adjusted horizontally by meansgofthescrew shaft 23 and-hand wheel 26;(F,i,gurea2) until the inner workpiece .51 issorcentercd. -The .clamp- .ing bolts 14 and, I=6aarethenstightened to clamp the assembliesin their: adiusted,po siticn.

The .set SCIQW11'93 (:Eiguregi) V. is; then: loosened land the eccentric shushinsdzevturned;unt i h outer workpiece .BI is placed withitscenter on the same horizontal level as the center of the inner workpiece 51, that is, at .the same center height. The pressure roll I29 is similarly adjusted by means of its eccentric bushing 92.

The work'head .I2 is now adjusted by swinging it around its vertical pivot I29 until it is presented to the grinding .wheel I6 at the proper angle to grind the conical surface 58 of the inner workpiece 51 to the correct taper. The support roll 95 and. pressure roll I29 are then adjusted :axially until the conical surface 92 of the outer workpiece BI islikewiseground tothe correct taper and size. Finally, the backing member 54 is adjusted axially (Figure 1) until the inner workpiece 51 is ground to the correct size. The machine is .now ready for precision grinding.

Inoperation, the workpieces are mounted in tandem in the parallel inclined troughs (not shown) above the arm H and pressure rolls I29 and I2 I, and the machine is started in operation. .By the conventional mechanism previously described, the arm I I5 is swung upwardly in timed relationship with the ejector 4| around the axis of the shaft I99 (Figure 2), permitting a pair of workpieces 51 and BI to drop downwardly into theposition shown in Figures 1, 2 and 5. The inner workpiece 51 comes to rest in the position shown'in Figure 3 with its periphery 69 resting upon the peripheral surfaces 32 and I99 of the regulating wheel or roll 39 and inner support roll 99 respectively, and with its inner face 56 in abutment with the contact or abutment face 55 of the .backing member 54. The inclination of thevarious axes of rotation (Figure 5), 'aspreviously described, causes the inner workpiece 51 to be urged into this position. The outer workpiece 6|, on the other hand,

'drops. into position with its periphery .65 engaging the peripheral surfaces 33 and 96 of the regulating wheel or roll' 35 and support roll 95 respectively, with its inner face 63 engaging the annular shoulders 34 and 91 thereof respectively. The same tilting of the various axes of rotation (Figure 5) as previously described, als constantly urges the outer workpiece GI into this abutting relationship. The carriage II is then moved forwardly in timed relationship toward the grinding wheel I6 and reciprocates axially in that position during grinding, thereby simultaneously grinding the internal conical surfaces 59 and 52 of the workpieces 51 and BI respectively.

When the grinding has been completed, as determined by the timing of reciprocation of the carriage II, the latter is automatically retracted. The cam mechanism by which the arm H9 is operated then comes into play to rotate the shaft I99 and swing the arm H5 and pressure rolls I29 and I 2| upwardly out of the way. Finally, the cam mechanism which swings the ejector shaft 36 in timed relationship with the previously described operation rotates the shaft 39 to swing thearm 49 and ejector 4I upwardly (Figure 2), pushing the workpieces 51 and BI upwardly to the right into parallel troughs which carry them away to suitable receptacles. Arcuate guides (not shown) are conventionally provided for assisting the ejection of the workpieces 51 and SI along arcuate paths substantially concentric with the axis of the regulating wheel 39.

the ground workpieces just ejected, the cam mechanism causes the arm H9 to be swung upwardly; moving the pressure rolls I29 and |2I downwardly into engagement with the new workpieces, whereupon the foregoing cycle of operations is repeated. Thus, the attachment of the present invention eifects the grinding of a pair of workpieces simultaneously with tapered internal surfaces instead of a single workpiece as in prior machines and as in the conventional machine to which the present attachment is applied.- The present invention, therefore, substantially doubles the production of each centerless grinding machine and effects a great saving both in the cost of the original equipment and in the cost of each workpiece.

Modification employing auxiliary backing memher for outer workpiece (Figures 6 and 7) 5 inclusive, except that the abutment flanges 98 and I22 with their abutment shoulders 91 and 623 are omitted. Instead, the respective rolls 95 and I29 are annularly grooved in the positions previously occupied by their respective flanges 98 and I22 as at I39 and I3I.

The vertical support 44 is provided with a laterally extended portion I32 (Figure 6) having a bore I33 in which is mounted an auxiliary backing shaft I34. The latter is held in position by a set screw I35 threaded through a bore I36 in a boss I31 on the laterally extended portion I32.

The forward end of the shaft I34 is provided with a threaded bore I38-into which is threaded a cap screw I39, the shank of which passes through an elongated slot I49 in a bifurcated abutment arm I4I this assembly constituting the auxiliary backing member I42. The bifurcated arm MI is provided with an arcuatelyextended end portion I43 having dome-like contact portions I44 at the upper and lower ends'thereof.

substance, and serve as abutment members engaging the rearward face 63 0f the outer workpiece 6I. In this way, the modification shown in Figures 6 and 7 differs from the form shown in Figures 1 to 5 inclusive, the abutment shoulders 91 and I23 on the flanges 98 and I22 of the support roll 95 and pressure rol1'I29 of the principal form of the invention being omitted; s

V The adjustments of the modification shown in Figures 6 and -7 are generally similar to those previously described in connection with Figures 1 to 5 inclusive, in that the face 55 of the backing member ,54 is trued and the support roll 99 and regulating wheel or roll 39 are adjusted to place the inner workpiece 51 concentric with the rotating member 54 as previously described. The two hardenedc'ontact portions I44'on the abutment arm I4I are then trued so as to be in the same plane as the abutment shoulder 34 of the regulating wheel 23 and also parallel with the contactspace 55 of the backing member 54. The outer rolls 95 and I29 are then adjusted by means of'th'eireccentric bushings I22 (Figure 4:) in the manner previously described, to place the outer workpiece BIT-at the same center height as the inner workpiece 51. Thefinner workpiece is adassume 9 justedr to be ground to the correct-1 taper" or its internal surface 58: by adjusting the worlshead I2 around its vertical pivot IsZm so asto. present the. internal surface 58 at the correct angle to the. grinding wheel lit". The outside workpiece is then ground to the correct. taper by adjusting the auxiliary backing. member I542. by moving the; shaft. I34 thereoi longitudinally in. the bore. I33 (Figure 6); The correct size thereof is obtained: by adjusting the amount the grinding head cross slid'e I4 is fed: transversely tothe. axis I'ZB of the grinding. wheel I26, To. grind the tapered internal surface of the. inner workpiece to. its correct size, the rotatable backing member 54 is moved longitudinally' along its. axis I2'5 The machine is now ready for production grinding;

The operation of the modification shovm Figures 6 and 7: is substantially the same as that of theform shown. in Figures 1 to. inclusive, and hence requires no repetition. The operation diftors only in. that the outer workpiece 6| is held against the contact points or: portions I144: on the auxiliary backing member I' l-2 instead of against the flanges 5E and I22 on thesupport 95 andzpressure roll. I526 rcspectively'in: Figures 1 to5 inclusive. I

Modification employing inner workpiece. as backmy member for outer workpiece (Figures 8 and 9) The modification shown in Figures 8 and 9 is generally similar to the modification shown in Figures 6 and 7, except that the auxiliary work support 42 and its associated parts are omitted. Instead, the rearward surface 63 of the outer workpiece 61 directly engages the outer surface 59 of the inner workpiece 5 1". For this reason, the shoulder 34 between the peripheral portions 32 and 33 of the regulating wheel or roll 36 is moved rearwardly a slight amount (Figure 8) so as to leave a gap or clearance I45 between the shoulder 34 and therearward surface 63 of the outer workpiece 6|.

The adjustment of the machine is substantially the same as that described'in connection with the modification shown in Figures 6 and 7 except that the procedurerelati-ng to the auxiliary backing member I42 is omitted, because of the absence of that member. In the modification of Figures 8 and 9, the axial thicknesses of the workpiece 51 must be carefully maintained within close tolerances because the axial thicknesses or the inner workpieces 51 directly determine the position axially which will be occupied by the outer workpieces B I by reason of the fact that the inner workpieces 51 serve as backing members for the outer workpieces 6|. 1

The operation of the modification shown in Figures 8 and 9 is also substantially the same as that set forth in connection with the principal form of the invention shown in Figures 1 to 5 inclusive, except that the procedure relating to the flanges 98 and M2 on the support roll 95 and pressure roll I is omitted because these flanges are lacking.

While I have shownand described my invention in detail, it is to be understood that the same is to be limited only by the appended claims, for many changes may be made without departing from the spirit and scope of 'my invention What I claim is:

1. An attachment for internallygrindinga pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roli, a backing member, and a driving struc ture: for one of said; rolls, said attachment comprising a rotary regulating device drivingly connectednto said driving structure and; having a plurality of radially offset; workpiece engaging paths. thereon, a backing member mounted on. one of said supporting structures and abutting one of said; workpieces; aaplurality of radially offset workpiece supports mounted on another of said supporting structures, and a plurality of radially oiiset. pressure: applicators mounted: on; anotherof said supporting structures; said workpieces being disposed in radially ofiset; relation-4 ship.- between said regulating deyzica. said workpiece supports; and said pressure applicators and in peripheral engagementtherewith.

2. An attachmentror internal-la grinding a pair of workpieces simultaneously on a centerless grinding machine. having, supporting structures for a-regulating; roll, a support; roll, a pressure roll, and a backing memben. and a. driving structure for one: of. said rollsm said. attachment: comprising a rotary regulating: device connected to said, driving structure and having a plurality of spaced peripheral workpiece. en-= gaging. paths thereon, a backing: member mounted on one side or said supporting structures and abutting one of said. workpieces, a plurality of oliset workpiece supports mounted onanother of said supporting structures, and. aplurality of ofiset. pressure applicators mounted on another of said supporting structures, said workpieces being disposed. in ofiset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

3. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing memben'and a driving structure for one of said rolls, said attachment comprising a rotary regulating device drivi'ngly connected to said driving structure and having a plurality of workpiece engaging paths thereon of different diameters, a backing member mounted on one of said supporting structures and abutting one. of said workpieces, a plurality of ofiset workpiece. supports mounted onan'otherof said supporting structures, and a plurality of ofiset pressure applicators mounted on another of said supporting structures, said workpieces being disposed inofiset relationship between said regulating device, said workpiece supportsand said pressure applicators and in peripheral engagement therewith.

4. An attachment ior internally grinding a pair of. workpieces simultaneously on a centerless grinding machine having supporting structures for a. regulating roll, a support roll, a pressure. roll, and a backing member, and a driving structure for one of said rolls,said attachment comprisinga rotary regulating device drivingly connected to said driving structure and having a plurality of stepped workpiece engaging 'paths thereon at different distances from the axis of rotation thereof, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of ofiset workpiece supports mounted on another of said supporting structures, and a plurality of offset pressure applicatorsmounted on another of said supporting structuressaid workpieces. being disposed in off S t relationship between said regulating device,

said workpiece supports and said pressure applicators and in peripheral engagement therewith.

5. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls, said attachment cornprisingv a rotary regulating device drivingly connected to said driving structure and having a plurality of radially offset workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of radially offset rotatable workpiece supports mounted on another of said supporting structures on spaced axes of rotation, and a plurality of radially offset pressure applicators mounted on another of said supporting structures, said workpieces being disposed in radially offset relationship between said regulating device, said workpiece supports and said pressure applicators and. in peripheral engagem'ent therewith.

6. An attachment for intern-ally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls, said attachment com prising a rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said'supporting structures and'abutting one of said workpieces, a plurality of offset rotatable workpiece supports mounted on another of said supporting structures on spaced axes of rotation, one of said workpiece supports having a shouldered abutment portion engageable with one of said workpieces, and a plurality of offset pressure applicators mounted on another of said supporting structures, said workpieces being disposed in offset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

'7. An attachment. for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for onev of said rolls, said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a plurality of radially offset workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of radially ofiset workpiece supports mounted on another of said supporting structures, and a plurality of radially ofiset rotatable pressure applicators mounted on another of said supporting structures on spaced axes of rotation, said workpieces being disposed in radially offset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

8. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls, said attachment comprising a rotary regulatingdevice drivingly connected to said driving structure and having a plurality of workpiece engaging paths, thereon,

a backing member mounted on one of said sup porting structures and abutting one of said workpieces, a plurality of offset workpiece supports mounted on another of said supporting structures, and a plurality of offset rotatable pressure applicators mounted on another of said supporting structures on spaced axes of rotation, one of said pressure applicators having a shouldered abutment portion engageable with one of said workpieces, said workpieces being disposed in offset relationship between said regulating device, said workpiece supports and said pres sure applicators and in peripheral engagement therewith.

9. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll and a backing member, and a driving structure for one of said rolls said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of offset workpiece supports mounted on another of said supporting structures, and a plurality of ofiset rotatable pressure applicators mounted on another of said supporting structures, one of said workpiece supports and one of said pressure applicators being rotatable on spaced axes of rotation relatively to the other support and applicator respectively, said workpieces being disposed in offset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

10. An attachment for internallygrinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll and a backing member, and a driving structure for one of said rolls said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of offset workpiece supports mounted on another of said supporting structures, and a plurality of ofiset rotatable pressure applicators mounted on another of said supporting structures, one of said workpiece supports and one of said pressure applicators-being rotatable on spaced axes of rotation relatively to the other support and applicator respectively, one of said workpiece supports and one of said pressure applicators each having a shouldered abutment portion engageable with one of said workpieces, said workpieces being disposed in offset relationship between said regulating device, said work piece supports and said pressure applicators and in peripheral engagement therewith.

11. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls said attachment comprising arotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of ofiset rotatable workpiece supports mounted on another of said supporting structures on spaced axes of rotation, an-eccentric member disposedbetween one of said workpiece supports and its supporting structure and adjustably rotatable relatively thereto, and a plurality of oflset pressure applicatorsmounted on another of said supporting structures, saidworkpieces being disposed in ofliset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

12. An attachment for internally grinding a pair of workpiecessimultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls said attachment comprising a rotary regulating device drivingly connected to said driving structure and havinga plurality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures andabutting one of said workpieces, a plurality of offset workpiece supports mounted on another of said supporting structures, a plurality of onset rotatable pressure applicators mounted on another of said supporting structures, and an eccentric member disposed between one of said pressure applicators and its supporting structure and adjustably rotatablerel- -atively thereto, said workpieces being disposed in oifset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

13. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls said attachment comprising a, rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engagingpaths thereon, a backing member mounted on one of said supporting structures and albutting one of said workpieces, a plurality of offset rotatable workpiece supports mounted on another of said supporting structures on spaced axes of rotation, an eccentric member disposed between one of said workpiece supports and its supporting structure and adjustably rotatable relatively thereto, a plurality of oifset rotatable pressure applicators mounted on another of said supporting structures, and an eccentric member disposed between one of said pressure applicators and its supporting structure and adjustably rotatable relatively thereto, said workpieces being disposed in oifset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

14. An attachment for internally grinding a pair of workpieces simultaneously on a, centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of offset workpiece supports mounted on another of said supporting structures, a plurality oi oflset pressure applicators mounted on another ofrsaid supporting structures, and an auxiliary backing member mounted on one of saidstructures and having an abutment portion extending between said workpieces and engaging'one of saidworkpieces, said workpieces being disposed in offset relationship between said regulatingdevlce, said workpiece supports and said pressure applicators'and in peripheral engagement therewith.

15. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure forone of said rolls, said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a murality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of onset workpiece supports mounted on anotherof said supporting structures, a plurality of onset pressure applicators mounted on another of said supporting structures, and an auxiliary backing member mounted onone of said structures and having an abutment portion with spaced contact portions extending between said workpieces and engaging one of said work'- pieces, said workpieces being disposed in oflset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

16. Anattachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures fora regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls, said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of offset workpiece supports mounted on another of said supporting structures, a plurality of offset pressure applicators mounted on another of said supporting structures, and an auxiliary backing member mounted on one of said structures and having an abutment portion extending between said workpieces and engaging one of said workpieces, said auxiliary backing member being adjustably movable axially relatively to the workpiece engaged thereby, said workpieces being disposed in ofiset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

17. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls, said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of ofiset rotatable workpiece supports mounted on another of said supporting structures on spaced axes of rotation, a plurality of offset pressure applicators mounted on another of said supporting structures, and an auxiliary backing member mounted on one of said structures and having an abutment portion extend- .ing between said workpieces and engaging one of said workpieces, said workpieces being disposed in offset relationship between said regulating device, said workpiece supports and said pressure :applicators and in peripheral engagement therewith.

a 18. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a. driving structure for one of said rolls, said attachment comprising a, rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said support ing structures and abutting one of said workpieces, a plurality of offset workpiece supports mounted on another of said supporting structures, a plurality of oiiset rotatable pressure applicator's mounted on another of said supporting structures on spaced axes of rotation, and an auxiliary backing member mounted on one of said structures and having an abutment portion extending between said workpieces and engaging one Of said workpieces, said workpieces bein disposed in offset relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith.

19. An attachment for internally grinding a pair of workpieces simultaneously on a. centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls, said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a plurality of workpiece engaging paths thereon, a backing member mounted on one of said supporting structures and abutting one of said workpieces, a plurality of offset rotatable workpiece supports mounted on another of said supporting workpiece supports and said pressure applicators and in peripheral engagement therewith.

20. An attachment for internally grinding a pair of workpieces simultaneously on a centerless grinding machine having supporting structures for a regulating roll, a support roll, a pressure roll, and a backing member, and a driving structure for one of said rolls, said attachment comprising a rotary regulating device drivingly connected to said driving structure and having a plurality of radially offset workpiece engaging paths thereon, a backing member mounted on one of said supporting structures, and a plurality of radially offset pressure applicators mounted on, another of said supporting structures, said workpieces being disposed in radially oii'set relationship between said regulating device, said workpiece supports and said pressure applicators and in peripheral engagement therewith, one of said workpieces being disposed in direct abutting relationship with the other workpiece adjacent thereto.

- ARTHUR F. MADISON.

REFERENCES CITED The following references are of record inthe file of this patent: V

UNITED STATES PATENTS Number Date Cramer June 26- 1945 

